Study on the Mechanisms of Adaptation of Cucumber Seedling Roots to Na_2CO_3 Stress

Cucumber cultivars Jinyou No.1 and Chun No.4 were grown in sand culture to study the mechanisms of adaptation of their seedling roots to Na2CO3 stress.The result showed that with the increase in Na2CO3 concentration,the relative water content of cucumber seedling roots increased first,and then dropped;root activity was decreased gradually,but SOD activity increased;relative conductivity,MDA content,soluble sugar content and proline content dropped first,and then increased.The result of principal component analysis demonstrated that relative conductivity,MDA content,proline content and relative water content of cucumber seedling roots were important indicators in Na2CO3 stress evaluation of cucumber seedlings.An analysis using the 5 physiological indicators showed that Na2CO3 tolerance of Jinyou No.1 was higher than that of Chun No.4.